@article{AlldrickLutz1989, author = {Alldrick, A. J. and Lutz, Werner K.}, title = {Covalent binding of [2-\(^{14}\)C]2-amino-3,8-dimethylimidazo[4,5-f]-quinoxaline (MeIQx) to mouse DNA in vivo}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-60832}, year = {1989}, abstract = {Fernale BALB/c mice were administered intragastrically with equimolar amounts of either [2-\(^{14}\)C]2-amino-3,8-dimethyi[ 4,5-J]qulnoxaline (MeiQx) or 2-acetylamino[9-\(^{14}\)C]fluorene (2AAF). DNA was isolated from tissues of mice killed either 6 or 24 h after administration. Analysis of liver DNA nucleotide digests by HPLC analysis revealed that all of the radioactivity was attributable to adduct formation. Tbe specific activities of DNA samples were converted to covalent bindlog indices (CBI, J.LIDOI adduct per mol DNA nucleotides/mmol chemical app6ed per kg animal body weight). CBI values of 25 and 9 were detennined for 2AAF and MeiQx in tbe llvers of mice killed 6 h after dosing. The values were in general agreement with the moderate carcinogenic potency of these compounds. The specific activities of DNA preparations obtained from the lddneys, spleens, stomachs, small intestines and large intestlnes of mice treated witb MeiQx and killed 6 h after doslng were S- to 35-times less tban those obtained witb the llver. DNA isolated from tbe lungs (a target organ for MeiQx tumorigenicity) of MeiQx-treated mice was not radiolabeUed at tbe limit of detection (CBI <0.3). With tbe exception of tbe gastrolntestinal tract, the specific activities of DNA samples isolated from mice killed 6 h after administration were higher than those from mice killed after 24 h.}, subject = {Toxikologie}, language = {en} } @article{Bach1989, author = {Bach, Ulrich}, title = {Oral rhetoric in writings for a mixed literate and illiterate audience}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-47124}, year = {1989}, abstract = {No abstract available}, language = {en} } @article{BaumhauerBuscheSponholz1989, author = {Baumhauer, Roland and Busche, Detlef and Sponholz, Barbara}, title = {Reliefgeschichte und Pal{\"a}oklima des saharischen Ost-Niger}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-55378}, year = {1989}, abstract = {Der gr{\"o}ßte Teil des zentralsaharischen Reliefs ist unter dem Einfluß nicht-arider Klimate gebildet worden. Andererseits gab es im Pleistoz{\"a}n {\"a}olisch gepr{\"a}gte aride Phasen, die extremer als heutige gewesen sind. Der Kenntnisstand zur Reliefgeschichte erlaubt es, daraus die Grundz{\"u}ge der Klimageschichte eines großen Teils der s{\"u}dlich-zentralen Sahara abzuleiten.}, subject = {Geographie}, language = {de} } @article{BenaventeDabauvalleScheeretal.1989, author = {Benavente, Ricardo and Dabauvalle, Marie-Christine and Scheer, Ulrich and Chaly, Nathalie}, title = {Functional role of newly formed pore complexes in postmitotic nuclear reorganization}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-40754}, year = {1989}, abstract = {Many nuclear proteins are released into the cytoplasm at prometaphase and are transported back into the daughter nuclei at the end of mitosis. To determine the role of this reentry in nuclear remodelling during early interphase, we experimentally manipulated nuclear protein uptake in dividing cells. Recently we and others have shown that signal-dependent, pore complex-mediated uptake of nuclear protein is blocked in living cells on microinjection of the lectin wheat germ agglutinin (WGA), or of antibodies such as PI1 that are directed against WGA-binding pore complex glycoproteins. In the present study, we microinjected mitotic PtKz cells with WGA or antibody PIt and followed nuclear reorganization of the daughter cells by immunofluorescence and electron microscopy. The inhibitory effect on nuclear protein uptake was monitored by co-injection of the karyophilic protein nucleoplasmin. When injected by itself early in mitosis, nucleoplasmin became sequestered into the daughter nuclei as they entered telophase. In contrast, nucleoplasmin was excluded from the daughter nuclei in the presence of WGA or antibody PI1 . Although PtKz cells with blocked nuclear protein uptake completed cytokinesis, their nuclei showed a telophaselike organization characterized by highly condensed chromatin surrounded by a nuclear envelope containing a few pore complexes. These findings suggest that pore complexes become functional as early as telophase, in close coincidence with nuclear envelope reformation. They further indicate that the extensive structural rearrangement of the nucleus during the telophase-G1 transition is dependent on the influx of karyophilic proteins from the cytoplasm through the pore complexes, and is not due solely to chromosome- associated components.}, language = {en} } @article{BenaventeScheerChaly1989, author = {Benavente, Ricardo and Scheer, Ulrich and Chaly, Nathalie}, title = {Nucleocytoplasmic sorting of macromolecules following mitosis: fate of nuclear constituents after inhibition of pore complex function}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-40777}, year = {1989}, abstract = {PtK2 cells in which pore complex-mediated transport is blocked by microinjection early in mitosis of a monoclonal antibody (specific for an Mr 68000 pore complex glycoprotein) or of wheat germ agglutinin (WGA) complete cytokinesis. However, their nuclei remain stably arrested in a telophase-like organization characterized by highly condensed chromatin and the absence of nucleoli, indicating a requirement for pore-mediated transport for the reassembly of interphase nuclei. We have now examined this requirement more closely by monitoring the behavior of individual nuclear macromolecules in microinjected cells using immunofluorescence microscopy and have investigated the effect of microinjecting the antibody or WGA on cellular ultrastructure. The absence of nuclear transport did not affect the sequestration into daughter nuclei of components such as DNA, DNA topoisomerase I and the nucleolar protein fibrillarin that are carried through mitosis on chromosomes. On the other hand, lamins, snRNAs and the p68 pore complex glycoprotein, all cytoplasmic during mitosis, remained largely cytoplasmic in the telophase-arrested cells. Electron microscopy showed the nuclei to be surrounded by a doublelayered membrane with some inserted pore complexes. In addition, however, a variety of membranous structures with associated pore complexes was regularly noted in the cytoplasm, suggesting that chromatin may not be essential for the postmitotic formation of pore complexes. We propose that cellular compartmentalization at telophase is a two-step process. First, a nuclear envelope tightly encloses the condensed chromosomes, excluding non-selectively all macromolecules not associated with the chromosomes. Interphase nuclear organization is then progressively restored by selective pore complex-mediated uptake of nuclear proteins from the cytoplasm.}, subject = {Cytologie}, language = {en} } @article{BernardsSchacklefordGerberetal.1989, author = {Bernards, R. and Schackleford, G. M. and Gerber, M. R. and Horowitz, J. M. and Friend, S. H. and Schartl, Manfred and Bogenmann, E. and Rapaport, J. M. and Mcgee, T. and Dryja, T. P.}, title = {Structure and expression of the murine retinoblastoma gene and characterization of its encoded protein}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61819}, year = {1989}, abstract = {No abstract available}, subject = {Physiologische Chemie}, language = {en} } @article{BorasioJohnWittinghoferetal.1989, author = {Borasio, Gian Domenico and John, Jacob and Wittinghofer, Alfred and Barde, Yves-Alain and Sendtner, Michael and Heumann, Rolf}, title = {ras p21 protein promotes survival and fiber outgrowth of cultured embryonic neurons}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-32621}, year = {1989}, abstract = {Although evidence obtained with the PC12 cell line has suggested a role for the ras oncogene proteins in the signal transduction of nerve growth factor-mediated fiber outgrowth, little is known about the signal transduction mechanisms involved in the neuronal response to neurotrophic factors in nontransformed cells. We report here that the oncogene protein T24-ras, when introduced into the cytoplasm of freshly dissociated chick embryonic neurons, promotes the in vitro survival and neurite outgrowth of nerve growth factor-responsive dorsal rootganglion neurons, brain-derived neurotrophic factor-responsive nodose ganglion neurons, and ciliary neuronotrophic factor-responsive ciliary ganglion neurons. The proto-oncogene product c-Ha-ras also promotes neuronal survival, albeit less strongly. No effect could be observed with truncated counterparts of T24-ras and c-Ha-ras lacking the 23 C-terminal amino acids including the membrane-an-choring, palmityl-accepting cysteine. These results sug-gest a generalized involvement of ras or ras-like proteins in the intracellular signal transduction pathway for neurotrophic factors.}, language = {en} } @article{BorkowskiSchneiderPressley1989, author = {Borkowski, John G. and Schneider, Wolfgang and Pressley, Michael}, title = {The challenges of teaching good information processing to learning disabled students}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62117}, year = {1989}, abstract = {A MODEL of good information processing is sketched, describing how metacognitive knowledge influences strategy selection and use. Three factors pose particular problems for learning disabled students as they attempt to acquire metacognitive knowledge and to use study strategies productively: neurological impairments; deficiencies in general world knowledge; and negative beliefs, attitudes, and styles that limit self-efficacy. Creating an educational atmosphere that explicitly builds conceptual (domain-specific) knowledge and teaches positive beliefs about learning potential is essential in promoting metacognitively-oriented instruction.}, subject = {Psychologie}, language = {en} } @inproceedings{BossertMeilerLaessleetal.1989, author = {Bossert, Sabine and Meiler, Caroline and Laessle, Reinhold and Ellgring, Heiner and Pirke, Karl-Martin}, title = {Responses to visual perception of food in eating disorders}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-58762}, year = {1989}, abstract = {No abstract available}, subject = {Psychologie}, language = {en} } @article{CarrKurtzSchneideretal.1989, author = {Carr, Martha and Kurtz, Beth E. and Schneider, Wolfgang and Turner, Lisa A. and Borkowski, John G.}, title = {Strategy acquisition and transfer among American and German children: Environmental influences on metacognitive development}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62082}, year = {1989}, abstract = {This study explored the differential effects of strategy training on German and American elementaryschool children and assessed the role of parents in the development of their children's strategic behavior and metacognition. 184 German and 161 American children were pretested on memory and metamemory tasks. Children were then assigned to either an organizational strategy training condition or a control condition. All children were tested on the maintenance and far-transfer of the strategy and task-related metamemory 1 week following training. Parents completed questionnaires about strategy instruction in the home. Strategy maintenance and metacognition were reassessed 6 months following training. German children were more strategic than American children. Instructed children performed better than control children. German parents reported more instruction of strategies in the home. These data suggest that formal education is responsible for aspects of cognitive development that have sometimes been viewed as a function of age.}, subject = {Psychologie}, language = {en} }